Database - Mengenal Kekangan Nilai pada Data

• Mengatur Agar Data Selalu Diisi

create table infoprib (
id_bin char(5) not null,
nama char(25) not null,
tgl_lahir date,
sex char(1));
what about…
insert into infoprib values
(‘HAKIM’, ‘Christine Hakim’,
‘1957-12-25’, ’W’);
what about…
insert into infoprib (id_bin,tgl_lahir,sex)
values (‘DREWB’,’1972-02-22’,’W’);
what about…
insert into infoprib (id_bin,nama) values (
‘DREWB’,’Drew Barrymore’);

• Menentukan Kunci Primer

create table infoprib (
id_bin char(5) not null primary key,
nama char(25) not null,
tgl_lahir date,
sex char(1));
what about … 2x
insert into infoprib (id_bin, nama)
values (‘STONE’, ‘Sharon Stone’);

• Membuat Kunci Komposit

create table main (
id_bin char(5) not null,
kode_film char(5) not null,
tahun integer,
peran char(25),
primary key (id_bin, kode_film));

• Membuat Nilai yang Unik

create table infoprib (
id_bin char(5) not null primary key,
nama char(5) not null unique,
tgl_lahir date,
sex char(1));

• Memberi Nilai Bawaan

create table infoprib (
id_bin char(5) not null primary key,
nama char(25),
tgl_lahir date,
sex char default ‘W’);
contoh:
insert into infoprib (id_bin,nama)
values (‘DREWB’,’Drew Barrymore’);
cek dengan:
select * from infoprib;

• Memvalidasi Nilai

create table infoprib (
id_bin char(5) not null primary key,
nama char(5) unique,
tgl_lahir date,
sex char(1) default ‘W’
check (sex=‘W’ or sex=‘P’));
what about…
insert into infoprib values (
‘DREWB’,’Drew Barrymore’,’1975-02-22’,’W’);
what about…
insert into infoprib values (
‘SYLVE’,’Sylvester Stallone’,’1946-07-06’,’L’);